From c1c8fdab46414e3518400d6ee18916d2444a06d7 Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Fri, 14 Sep 2012 18:56:46 +0000 Subject: compat/vsnprintf: return number of bytes required on truncation. This conforms to C99, but requires Windows >= XP. Signed-off-by: Derek Buitenhuis --- compat/msvcrt/snprintf.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'compat') diff --git a/compat/msvcrt/snprintf.c b/compat/msvcrt/snprintf.c index 2cdec74b39..0af7b54353 100644 --- a/compat/msvcrt/snprintf.c +++ b/compat/msvcrt/snprintf.c @@ -26,6 +26,10 @@ #include "libavutil/error.h" +#if !defined(va_copy) && defined(_MSC_VER) +#define va_copy(dst, src) ((dst) = (src)) +#endif + int avpriv_snprintf(char *s, size_t n, const char *fmt, ...) { va_list ap; @@ -42,9 +46,10 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt, va_list ap) { int ret; + va_list ap_copy; if (n == 0) - return 0; + return _vscprintf(fmt, ap); else if (n > INT_MAX) return AVERROR(EOVERFLOW); @@ -55,9 +60,11 @@ int avpriv_vsnprintf(char *s, size_t n, const char *fmt, * _snprintf/_vsnprintf() to workaround this problem. * See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */ memset(s, 0, n); - ret = _vsnprintf(s, n - 1, fmt, ap); + va_copy(ap_copy, ap); + ret = _vsnprintf(s, n - 1, fmt, ap_copy); + va_end(ap_copy); if (ret == -1) - ret = n; + ret = _vscprintf(fmt, ap); return ret; } -- cgit v1.2.3